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Chapter 3 Plants. Characteristics of Plants. Plants are multicellular organisms A plant cell has a nucleus and a cell wall Plants are producers - they get their energy from the sun Plant life cycles have 2 stages. Vascular System. like the veins of the plant
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Characteristics of Plants • Plants are multicellular organisms • A plant cell has a nucleus and a cell wall • Plants are producers - they get their energy from the sun • Plant life cycles have 2 stages
Vascular System • like the veins of the plant -- xylem - goes from the roots up to the leaves -- phloem - goes from the leaves down to the rest of the plant
Photosynthesis • the process by which plants make their own food, using sunlight, water and carbon dioxide --photosynthesis takes place in the leaves of plants
Transpiration • when plants release water vapor into the air -- transpiration takes place in the stomata (part of the leaf) -- stomata open lets more water out -- stomata closed means less water out
Purpose of the Stem • provide structure and support for the plant • storing food • holding the vascular system • growing leaves
First plants • Plant species adapted to life on land.----all plants originally lived in the water! • Mosses came before ferns
Mosses • mosses do not have a vascular system - so, they cannot grow very tall or very large • mosses reproduce with spores (just like the mushroom!) • mosses reproduce both sexually and asexually
Ferns • ferns have a vascular system – so they can grow to be very large • ferns also reproduce with spores • ferns also reproduce sexually and asexually
Important Terms • Seeds – a young plant inside a protective coat • Embryo – the immature form of an organism that has the ability to grow and develop (some embryos are inside seeds) • Germination – the beginning growth of a new plant (from a spore or a seed)
Gymnosperm • plants that reproduce with seeds that are not inside fruit (“naked seed”) -- gymnosperms have been on earth for more than 250 million years ---examples: ginkoes, cycads, and conifers like pine trees, redwood trees, fir and spruce trees {conifers are trees that produce cones to hold the seeds (pine cone)} cycad
Angiosperm • a plant that produces flowers and fruit --flower – both male and female cells are inside of a flower -- fruit – the fertilized egg of a plant which holds the seed
Flower • petal– the leaf-like structures around the pistil • stamen– the male reproductive part of a flower • pistil– the female reproductive part of a flower • nectar– the sugary liquid at the bottom of a flower
Fruit • some plants have many seeds inside of their fruit • some plants only have one seed inside their fruit • some fruits are called “fleshy” fruits • some fruits are called “dry” fruits
Animals spread pollen and seeds • when an insect flies onto a flower to get the nectar it picks up some of the pollenon its body and takes it to another flower • when animals eat fruit they often eat the seeds too – the seeds go through their digestive system and are eventually deposited on the ground in their waste • birds also help to spread seeds to other locations, either in their waste or from dropping a seed they were trying to eat
Humans depend on plants for their survival • food– people eat many types of plants (especially angiosperms) • oxygen– plants take in our carbon dioxide and provide us with oxygen during photosynthesis • Energy– natural gas and coal are made from the dead and decaying remains of plants deep beneath earth’s surface • soil– a natural resource that is also made from decaying plants